Owing to generalization of information communication services, the demands for various communication services are rapidly increased such as multimedia services, high quality services, and the like. Researches on variety of wireless communication techniques in various fields are in progress to satisfy such demands.
One technique of securing reliability of communication is to obtain diversity gain by repeatedly transmitting the same data. By transmitting same data through multiple paths, data can reliably be reconstructed since data through some path can be reliable although data through the other paths are erroneous. An advantage of the diversity is to stably transmit and/or receive data through multiple paths independent of each other. Examples of the diversity technique include frequency diversity, time diversity and spatial diversity. The spatial diversity employs multiple transmit antennas.
Another technique of securing reliability of communication is hybrid automatic repeat request (HARQ) which combines forward error correction (FEC) and automatic repeat request (ARQ). The HARQ enhances the reliability by re-transmitting data when the data include decodable errors. An example of the HARQ is disclosed in D. Chase, Code Combining: A maximum-likelihood decoding approach for combining an arbitrary number of noisy packets, IEEE Trans. on Commun., Vol. 33, pp. 593-607, May, 1985.
Generally, a base station provides services for one or more cells. The base station can provide services to a plurality of users. In a service from the base station to a user or a service from a user to the base station, a service for another user can be considered as interference. Interference generated by a user located in another cell is referred to as inter-cell interference, and interference generated by a user located in the same cell is referred to as intra-cell interference.
In diversity or HARQ, link performance can be deteriorated due to the inter-cell interference or intra-cell interference. A method is sought for mitigating interference generated by other users.